表面晶体修饰Na3 V2 (PO4) 3到造中间Na2 V2 (PO4) 3阶段向高速储存阶段进行
Hui Zhang1, Lei Wang2, Linlin Ma1
1Department of Chemistry, College of Science, Hebei Agricultural University, Baoding, 071001, China.
Advanced science (Weinheim, Baden-Wurttemberg, Germany)
|November 24, 2023
概括
封装在化碳纳米 (N-NVP/N-CN) 中的表面修饰的酸 (NVP) 提高了离子电池的性能. 这种正极材料在高速应用中表现出更好的导电性和稳定性.
科学领域:
- 材料科学 材料科学 材料科学
- 电化学 电化学 电化学
- 纳米技术纳米技术
背景情况:
- 酸 (Na3V2(PO4) 3,NVP) 具有较差的电子和离子导电性,限制了其在离子电池中的使用.
- 在NVP中,双相反应机制对高效的离子扩散和电荷传输提出了挑战.
研究的目的:
- 通过解决其导电性限制,提高NVP的电化学性能.
- 开发用于离子电池的新型阴极材料,以提高速度能力和循环稳定性.
主要方法:
- 合理的构建表面胺的NVP被胺的碳纳米封装 (N-NVP/N-CN).
- 利用现场的X射线衍射 (XRD) 和密度函数理论 (DFT) 计算来研究反应机制和中间阶段.
- 电化学测试用于评估特定容量,速率性能和长期循环稳定性.
主要成果:
- 由于表面晶体的修饰和多孔碳封装,N-NVP/N-CN材料表现出显著增强的电子和离子导电性.
- 在现场XRD和DFT证实了在三相反应期间形成稳定的Na2V2(PO4) 3中间相,其能量屏障降低.
- 实现了高的特异性容量 (例如,1C时119.7 mAh g-1;200C时75.3 mAh g-1) 和出色的循环稳定性 (例如50C时10,000个循环后84.6 mAh g-1).
结论:
- 表面晶体修饰和兴奋剂是改善离子电池NVP电化学性能的有效策略.
- N-NVP/N-CN阴极展示了高性能离子储能应用的潜力.
- 这项工作为通过受控表面工程和相位操纵设计先进的阴极材料提供了新的途径.
相关概念视频
Ionic Crystal Structures
14.4K
Ionic crystals consist of two or more different kinds of ions that usually have different sizes. The packing of these ions into a crystal structure is more complex than the packing of metal atoms that are the same size.
Most monatomic ions behave as charged spheres, and their attraction for ions of opposite charge is the same in every direction. Consequently, stable structures for ionic compounds result (1) when ions of one charge are surrounded by as many ions as possible of the opposite...
Most monatomic ions behave as charged spheres, and their attraction for ions of opposite charge is the same in every direction. Consequently, stable structures for ionic compounds result (1) when ions of one charge are surrounded by as many ions as possible of the opposite...
14.4K
Qualitative Analysis
22.4K
For solutions containing mixtures of different cations, the identity of each cation can be determined by qualitative analysis. This technique involves a series of selective precipitations with different chemical reagents, each reaction producing a characteristic precipitate for a specific group of cations. Metal ions within a group are further separated by varying the pH, heating the mixture to redissolve a precipitate, or adding other reagents to form complex ions.
For instance, group IV...
For instance, group IV...
22.4K
Recrystallization: Solid–Solution Equilibria
1.1K
Recrystallization is a purification technique used to separate impurities from solid compounds. In this technique, no chemical reactions occur. Instead, it exploits physical properties only, specifically, the solubility differences between the desired compound and impurities, either at a single temperature or at different temperatures, and under other selected conditions. The solid-solution equilibrium (solubility equilibrium) of each component in the solution represents a binary phase...
1.1K
Crystal Growth: Principles of Crystallization
2.0K
Crystallization is a phase transformation process in which crystals are precipitated from a supersaturated solution or formed from other sources. During crystallization, atoms or molecules arrange themselves into a well-defined, rigid crystal lattice to minimize energy.
Initiating crystallization involves manipulating the concentration of the solute and the temperature of the solution. Since crystal growth occurs when the ratio of concentration and solubility of the solute in the solvent...
Initiating crystallization involves manipulating the concentration of the solute and the temperature of the solution. Since crystal growth occurs when the ratio of concentration and solubility of the solute in the solvent...
2.0K
Washing, Drying, and Ignition of Precipitates
924
After filtration, the precipitate is washed to remove coprecipitated impurities and any remaining mother liquor. Colloidal precipitates, such as silver chloride, are washed with an electrolyte (such as dilute nitric acid) to prevent the peptization of the precipitate. In the case of slightly soluble precipitates, the wash solution contains a common ion to reduce solubility. Lead sulfate, which is slightly soluble in water, is washed with dilute sulfuric acid. Similarly, wash solutions may be...
924


